Ihave canon 400 problems. e051, e901, e805 problems frequently please suggest me

Hello,
by the look at your problems:

E051 - Horizontal registration sensor problems
E001 - Fixing temperature faulty
E805 - The Fan rotation problems

It can be that You have problems with DC contoller ( main pcb ) or the copier is in worst condition and there are faults on every segment.

For E001, you can try to reset error:

1. The following error codes cannot be reset by merely turning off and then on the main power.
They require resetting in service mode:
E000, E001, E002, E003, E004, E032, E717
1) Start service mode, and select COPIER>FUNCTION>CLEAR>ERR.
2) Press the OK key.
3) Turn off and then on the main power.
2. Error codes other than the above may be reset by turning off and then on the main power.
n Detail Code
Some error codes offer detail codes, which may be checked in service mode:
COPIER>DISPLAY>ERR (3rd block from the right)



BUT I THINK THAT THE BEST SOLUTION IS TO CALL SERVICE TO RECTIFY THE PROBLEM OR YOU BUY NEW MACHINE:..

Hope that helps!